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A lit-element based version of react-inspector





A custom element, lit-element based, version of react-inspector

Power of Browser DevTools inspectors right as a custom element.

� Status: In Development

granite-inspector is currently in development. We encourage you to use it and give us your feedback, but there are things that haven't been finalized yet and you can expect some changes.

Published on npm Published on

Usage example

  <granite-object-inspector data='["a", "b", { "c": "d", "e": "f", "g": { "h": "i", "j": "k"}}]'></granite-object-inspector>


Install the component using npm:

$ npm i @granite-elements/ace-widget --save

Once installed, import it in your application:

import '@granite-elements/ace-widget/ace-widget.js';

Running demos and tests in browser

  1. Fork the ace-widget repository and clone it locally.

  2. Make sure you have npm and the Polymer CLI installed.

  3. When in the ace-widget directory, run npm install to install dependencies.

  4. Serve the project using Polyumer CLI:

    polymer serve --module-resolution node --component-dir node_modules

  5. Open the demo in the browser


<granite-inspector />

A shorthand for the inspectors.

  • <granite-inspector/> is currently equivalent to <granite-inspector-object>
  • DOM and table mode are under active development

<granite-inspector-object />

Like console.log. Consider this as a glorified version of <pre>JSON.stringify(data, null, 2)</pre>.

How it works

Tree state is saved at root. If you click to expand some elements in the hierarchy, the state will be preserved after the element is unmounted.


The component accepts the following props:

data {Object}: the Javascript object you would like to inspect

name {String}: specify the optional name of the root node, default to undefined

expandLevel {Number}: an integer specifying to which level the tree should be initially expanded.

expandPaths {String|Array}: an array containing all the paths that should be expanded when the component is initialized, or a string of just one path

  • The path string is similar to JSONPath.
    • It is a dot separated string like $ $ expands the path $ where $ refers to the root node. Note that it only expands that single node (but not all its parents and the root node). Instead, you should use expandPaths={['$', '$.foo', '$']} to expand all the way to the $ node.
    • You can refer to array index paths using ['$', '$.1']
    • You can use wildcard to expand all paths on a specific level
      • For example, to expand all first level and second level nodes, use ['$', '$.*'] (equivalent to expandLevel={2})
  • the results are merged with expandLevel

showNonenumerable {Boolean}: show non-enumerable properties.

sortObjectKeys {Boolean|Function}: Sort object keys with optional compare function.

nodeRenderer {Function}: Use a custom nodeRenderer to render the object properties (optional)

  • Instead of using the default nodeRenderer, you can provide a custom function for rendering object properties. The default nodeRender looks like this:

      import './granite-inspector-object-label';
      import './granite-inspector-object-root-label';
      const defaultNodeRenderer = ({ depth, name, data, isNonEnumerable }) => {
          return html`
              ${depth === 0 ?
                  name=${name} data=${data}></granite-inspector-object-root-label>` :
                      name=${name} data=${data} isNonEnumerable=${isNonEnumerable}></granite-inspector-object-label>`


By specifying the theme prop you can customize the inspectors. theme prop can be

  1. a string referring to a preset theme ("chromeLight" or "chromeDark", default to "chromeLight")
  2. or a custom object that provides the necessary variables. Checkout src/styles/themes for possible theming variables.

Example 1: Using a preset theme:

<granite-inspector theme="chromeDark" data='{"a": "a", "b": "b"}'></granite-inspector>


Type of inspectors:

  • Tree style
    • common objects
    • DOM nodes
  • Table style
    • Column resizer
  • Group style


  1. Fork it!
  2. Create your feature branch: git checkout -b my-new-feature
  3. Commit your changes: git commit -m 'Add some feature'
  4. Push to the branch: git push origin my-new-feature
  5. Submit a pull request :D


MIT License


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  • @polymer/lit-element#0.5.2
  • @polymer/polymer#^3.0.0
MIT License


Polymer 3.0+
Browser Independent

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